Process of dyeing acrylonitrile fibers



PROCESS on exams aenrrorurann means Elmer H. Rossin, Melrose, Mass,assignor to Monsanto Chemical Company, St. Louis, Me, a corporation ofDelaware No Drawing. Appiication August 31, 1951, Serial No. 244,731

9 Claims. (Cl. 3-55) mers or heteropolymers containing combinedacrylonitrile are exceedingly difficult to dye with conventionaldyestuffs. For example, they are barely tinted with direct cottondyestuffs. It has been proposed heretofore to dye such textile materialswith special dyestuffs. However, the dyestuffs heretofore proposed arequite expensive and increase the cost of processing the textile materials considerably above the processing costs of conventional naturalfibers which are dyed readily with inexpensive dyestuffs. The directcotton dyes are among the most inexpensive dyestuffs but it has not beenpossible heretofore to use such dyestuffs per se on textiles composed ofhomopolymers and heteropolymers of acrylonitrile since the depth of thedye shade produced is unsatisfactory for commercial purposes.

It is one object of this invention to provide processes for dyeingtextile materials composed partly or wholly of homopolymers ofacrylonitrile and/ or heteropolymers containing combined acrylonitrilewith direct cotton dyestuffs.

It is a further object of this invention to provide processes for dyeingtextile materials composed partly or Wholly of homopolymers ofacrylonitrile and/or heteropolymers containing combined acrylonitrilewith direct cotton dyestulfs to obtain a materially deeper dye shade onsuch textile materials than has been possible heretofore in the use ofdirect cotton dyestuffs per se.

It is a further object of this invention to provide a textile materialcomposed partly or wholly of homopolymers of acrylonitrile and/orheteropolymers containing combined acrylonitrile dyed with direct cottondyes, and

which has a satisfactory depth of dye shade.

Still further objects and advantages of this invention will appear inthe following description and the appended claims.

The processes of this invention are carried out, in general, byimmersing a textile material composed wholly or partly of homopolymersof acrylonitrile and/ or hetero polymers containing combinedacrylonitrile in an aqueous bath containing a direct cotton dyestuff inthe presence of a water-soluble quaternary phosphonium salt until amajor proportion of the dyestulf in the bath has exhausted on thetextile material, after which the textile material is dried. The dyebath is maintained at an elevated temperature, and preferably at theboil, during the dyeing operation.

- The term textile material as employed herein and in the appendedclaims is intended to include unspun fibers, yarns, continuous filamentsand fabrics. The present invention is directed to the dyeing of textilematerials 1 which contain at least 10% by weight of fiber-forminghomopolymers of acrylonitrile and/or heteropolymers nited States Patentcontaining combined acrylonitrile, and is particularly directed to thedyeing of textile materials which contain at least 10% by weight offiber-forming heteropolymers composed of at least 60% by weight ofacrylonitrile and 40% by weight or less of an unsaturated organiccompound copolymerizable therewith and having the grouping CH2= such as,for example, a vinyl or vinylidene compound. Since fiber-formingheteropolymers containing between about and 99% by weight ofacrylonitrile and 15 to 1% by weight of a compound having the groupingCH2=C such as vinyl or vinylidene compounds, copolymerizable therewithhave exceptionally desirable textile properties and are particularlyamenable to the dyeing processes of this invention, it is preferred touse textile materials composed of at least 10% by weight of suchheteropolymers in the processes of this invention.

The compound having the grouping CH2=C such as vinyl or vinylidenecompounds which are copolymerizable with acrylonitrile to formfiber-forming heteropolymers include styrene, nuclear-substitutedstyrenes such as the alkyl and chloro nuclear-substituted styrenes,vinyl chloride, vinyl acetate, divinyl benzene, alkyl acrylates such asmethyl acrylate and ethyl acrylate, vinyl pyridine, vinyl ethers such asvinyl methyl ether and vinyl butyl ether and the like; alkylmethacrylates such as methyl methacrylate, vinylidene chloride and thelike.

A wide variety of textiles may be blended with homopolymers ofacrylonitrile. and/or heteropolymers containing combined acrylonitrile,in amounts up to by weight to form the textile materials defined above.As examples of such textiles may be mentioned fibers or yarns comprisedof natural textiles such as cotton, linen, wool or other animal fibers,or synthetic textiles such as viscose and cuprammonium rayon, celluloseacetate, casein, synthetic fiber-forming polyamides such aspolyhexarnethylene-adipamideand fiber-forming condensation products ofethylene glycol and terephthalic acid.

In carrying out the processes of this invention,'the quaternaryphosphonium salt, which is an essential ingredient during the dyeingoperation, may be incorporated in the textile materials by adding thesalt to the spinning solution from which the staple fibers or filamentsof the homopolymers of acrylonitrile or heteropolymers containingcombined acrylonitrile are prepared, or by spraying or immersing thetextile materials with or in a solution, preferably an aqueous solution,of the quaternary phosphonium salt prior to the dyeing operation, or thequaternary phosphonium salts may be added directly to the aqueous dyebath containing the direct cotton dyestuff. The latter procedure, thatis, the procedure of adding the quaternary phosphonium salt to theaqueous dye bath is preferred since it is the simplest procedure andgives the best results.

The amount of the quaternary phosphonium salt used may be variedconsiderably. In general, the depth of dye shade is increased byincreasing the amount of quaternary phosphonium salt employed until theoptimum amount of the salt is used after which the depth of dye shade isnot improved appreciably. It is usually desirable to employ at least1.0% by weight of the salt, based on the dry weight of the textilematerial. However, in some instances it is possible toobtainsatisfactory results by using as little as 0.1% by weight of thesalt, based on the dry weight of textile materials. There is no limitingfactor on the upper limit of the salt'except its solubility in water andeconomical considerations. However, it is usually not necessary toemploy more than 15% by weight of the salt, based on the dry weight ofthe textile material. Best results are obtained by using about 4 to 10%by weight of the quaternary phosphonium salt 3 based on the dry weightof the textile materials and accordingly such amounts are preferred.

The above amounts of the quaternary phosphonium salts are readilyincorporated in or on the textile materials prior to the dyeingoperation or are incorporated directly in the aqueous dye bath.

The amount of direct cotton dyestuff used in the aqueous dye bath may bevaried to some extent depending primarily on the particular dyestufiemployed and the depth of dye shade desired. In general, from about 0.5to 5% by weight of the dyestuif, based on the dry weight of the textilematerial to be dyed, gives satisfactory results.

As in conventional dyeing practice, it is desirable to employ so-calledlong baths, that is, between about to 150 parts by weight of the dyebath for each part by Weight of textile material. Best results areobtained in most instances by using from about to 70 parts by weight ofdye bath for each part by weight of textile materials.

The aqueous dye bath may contain the customary dye bath additives suchas alkali metal salts, for example, soduim sulfate or sodium chloride toassist in the exhausting the dyestulfs on the textile material, andanion active surface agents to assist in the dyeing operation.

To facilitate the exhaustion of the dyestuif on the textile material itis desirable to maintain the dye bath at an elevated temperature duringthe dyeing operation. In general satisfactory results are obtained bymaintaining the dye bath at a temperature above 70 C. However, n

the dyeing proceeds much more rapidly at the boiling point of the dyebath and accordingly it is preferred to carry out the dyeing operationat the boil. The dyeing operation is usually completed in from 15 to 60minutes depending on the operating conditions employed, and theconcentrations of quaternary phosphonium salt and dyestuff used,although longer periods may be used.

After a major portion of the dyestuif has exhausted on the textilematerial or the desired depth of dye shade is attained, the dye bath iscooled and the textile material is then rinsed with water and dried atconventional drying temperatures.

By carrying out the dyeing processes described herein, it is possible todye textile materials composed of at least 10% by weight offiber-forming homopolymers of acrylonitrile or heteropolymers containingmore than 60% combined acrylonitrile evenly and uniformly with directcotton dyestuffs to provide textile materials having deep dye shades.Moreover, it is possible in some instances to completely exhaust thedyestuff from the dye bath.

A further understanding of the processes described herein will beobtained from the following specific examples which are intended to beillustrative of this invention, but not limitative of the scope thereof,parts and percentages being by weight unless otherwise specified.

Example I Five and eight-tenth parts of a yarn composed entirely ofstaple fibers of a copolymer of 90% of acrylonitrile and 10% of vinylchloride were immersed in 290 parts of an aqueous bath containing 20% ofsodium sulfate,

- moved from the bath, rinsed in water and then dried at a temperatureof 60 C.

The dyed yarn had a satisfactory dye shade, whereas an equivalent yarndyed in the same manner but without the use of the phosphonium salt wasbarely tinted during the dyeing operation and had an unsatisfactory dyeshade.

are useful include compounds having the general formula:

Example II Ten parts of a fabric containing yarns composed of 10% woolfibers and staple fibers of a copolymer of acrylonitrile and 5% vinylpyridine were immersed in 600 parts of an aqueous bath containing 20% ofsodium sulfate, 3% of chlorantine Fast Red (Colour Index Number 278),based on the dry weight of the fabric, and 5% of 4-bromobenzyl tris(diethylamino) phosphonium chloride, based on the dry weight of thefabric. The dye bath was brought to a boil within a period of 10 minutesand then maintained at the boil for a period of 45 minutes, after whichis was cooled for 20 minutes. The fabric was then removed from the bath,rinsed with water and squeezed to remove excess water. The fabric wasnext dried at a temperature of 60 C.

The resulting fabric was dyed evenly and had a satisfactory dye shade,whereas an equivalent fabric dyed in the same manner but Without the useof the phosphonium salt was merely tinted and did not have asatisfactory dye shade.

Example Ill Ten parts of staple fibers consisting of 8 parts of staplefibers of a copolymer of 95% acrylonitrile and 5% styrene and 2 parts ofviscose rayon staple fibers were immersed in 400 parts of an aqueousbath containing 20% sodium sulfate, 4% of chlorantine Fast Blue 4 GL(Colour Index Number 533), based on the dry weight of the fibers, and10% of benzyl tris (di-isopropylamino) phosphonium bromide, based on thedry weight of the fibers. The bath was brought to a boil within a periodof 15 minutes and maintained at the boil for a period of 40 minutes,after which it was cooled for 20 minutes. The fibers were then removedfrom the bath, rinsed with water and finally dried at 70 C.

useful in the processes of this invention including compounds having thegeneral formula where R represents an alkyl group containing from 1 to 4carbon atoms, R represents an alkyl group containing from 6 to 20 carbonatoms and where X is a bromine, chlorine or iodine atom. As examples ofsuch compounds may be mentioned decyl trimethyl phosphonium iodide,bromide or chloride, dodecyl, trimethyl phosphonium iodide, bromide orchloride, decyl trimethyl phosphonium bromide or chloride and the like.

Another class of quaternary phosphonium salts which atoms, R is anaryl-alkyl radical and X is a bromine, chlorine or iodine atom. Asexamples of such compounds may be mentioned benzyl trimethyl phosphoniumchloride or bromide, benzyl triethyl phosphonium chloride, bromide oriodide and the like.

Still another class of quaternary phosphonium salts which are suitablein the processes of this invention are nitrogen containing quaternaryphosphonium salts, particularly compounds having the general formula:

)NRQ' RPLNRII E i NR2 where R is an alkyl group containing from 6 to 22carbon atoms, R is an alkyl group containing from 1 to 4 carbon atomsand X is a chlorine or bromine atom. This class of compounds, which maybe designated alkyl tris (dialkylamino) phosphonium chlorides orbromides, include such compounds as n-hexyl tri (dipropylamino)phosphonium bromide or chloride, n-heptyl tris (dimethyl-amino)phosphonium chloride or bromide, ndodecyl tris (diethylamino)phosphonium chloride or bromide and the like. Such compounds areobtained, in general, by reacting an alkyl bromide or chloridecontaining from 6 to 22 carbon atoms with a heXa-alkyl phosphoroustriamide having the formula: P(NR2)3 where R has the significancedescribed above, the reaction being carried out at a temperature betweenabout 80 and 250 C. until the corresponding phosphonium halide isformed. Further examples of such halides and methods of preparing thesecompounds are giving in the co-pending appiication Serial No. 239,175 ofWilliam T, Dye, Jr., filed July 28, 1951.

A preferred class of quaternary phosphonium salts for 'se in theprocesses of this invention are the nitrogen containing phosphoniumhalides having the general formula:

where R and R are chlorine, bromine and hydrogen atoms or alkyl radicalscontaining from 1 to 5 carbon atoms, R" represents an alkyl radicalcontaining from 1 to 4 carbon atoms and X is a chlorine or bromine atom.As examples of such compounds may be mentioned benzyl tris(dimethylamino) phosphonium chloride or bromide, Z-chlorobenzyl tris(di-isopropylamino) phosphonium chloride or bromide, 3-bromobenzyl tris(diethylamino) phosphonium chloride or bromide, 4-ethylbenzyl tris(diethylamino) phosphonium chloride or bromide and the like. This classof compounds are prepared, in general, by reacting the correspondingbenzyl halide with a hexalkylphosphorous triamide in which the alkylgroups contain from 1 to 4 carbon atoms, the reaction being carried outat normal or elevated temperatures in the presence or absence ofsolvents or diluents. Further examples of this class of compounds andmethods for preparing such compounds are given in the co-pendingapplication Serial No. 223,449 of William T. Dye, Jr., filed April 27,1951, and the continuation-in-part application Serial No. 278,- 757,filed March 26, 1952, now U. S. Patent No. 2,703,814,

A wide variety of direct cotton dyestuffs may be used, in addition tothose described in the examples, to dye the textile materialshereinbefore referred to in accordance with the processes of thisinvention. Suitable direct dyestuffs are listed below:

Name of dyestutf Color Index Number Amanil Blue 2G 406 Amanil FastScarlet B 382 Soldantine Blue R 319 Vegentine Fast Brown B 561 PyrazolFast Brilliant Blue A 319 Trisulfon Garnet BR 375 lnterchem Direct BrownCN 596 Fastusol Red 4 BA-CF 278 Pontarnine Black BCN 581 Diphenyl DarkGreen BN 583 Pontamine Brown BCW 561 Direct Blue 313 477 Direct Violet3R 385 Other direct cotton dyestuff may be used in the pro" cesses ofthis invention as will be apparent to those skilled in the art.

Various modifications and changes may be made in the processes and dyedtextile materials described herein as will be apparent to those skilledin the art to which this invention appertains without departing from thespirit and intent of the invention described herein. It is to beunderstood therefore that it is not intended to limit this inventionexcept by the scope of the appended claims.

What is claimed is:

1. A dyeing process which comprises immersing textile materials composedof at least 10% by weight of a fiberforming hydrophobic heteropolymercontaining at least 60% by weight of acrylonitrile and not more than 40%by weight of a compound copolymerizable therewith having the groupingCH2= and containing a watersoluble benzyl tris (dialkylamino)phosphonium halide having the general formula:

wherein R and R are selected from the group consisting of chlorine,bromine, and hydrogen atoms and alkyl radicals containing from 1 to 5carbon atoms, R" is an alkyl radical containing from 1 to 4 carbonatoms, and X is selected from the group consisting of chlorine andbromine, in an aqueous bath containing a direct cotton dyestuif, raisingthe temperature of the dye bath above 70 C., maintaining the textilematerials in contact with the bath at a temperature above 70 C. untilthe textile materials are dyed, and thereafter rinsing and drying saidmaterials.

2. A dyeing process which comprises immersing textile materials composedof at least 10% by weight of a fiberforming hydrophobic hetero-polymercontaining at least 60% by weight of acrylonitrile and not more than 40%by weight of a compound copolymerizable therewith having the groupingCH2=C in an aqueous solution of a water-soluble benzyl tris(dialkylamino) phosphonium halide having the general formula:

wherein R and R are selected from the group consisting of chlorine,bromine, and hydrogen atoms and alkyl radicals containing from 1 to 5carbon atoms, R" is an alkyl radical containing from 1 to 4 carbonatoms, and X is selected from the group consisting of chlorine andbromine, thereafter immersing said textile materials in an aqueous bathcontaining a direct cotton dyestuff, raising the temperature of the dyebath above 70 0, maintaining the textile materials in contact with thebath at a temperature above 70 C. until the materials are dyed and thenrinsing and drying said materials.

3. A process of dyeing textile materials composed of at least 10% byweight of a fiber-forming hydrophobic substance selected from the groupconsisting of homopolymers of acrylonitrile and heteropolymers of atleast 60% by weight of acrylonitrile and not more than 40% by weight ofa compound copolymerizable therewith and having the grouping CH2=C whichcomprises immersing said textile materials in an aqueous bath containinga direct cotton dyestuff and in the presence of 0.1 to 15% by weight,based on the dry weight of said textile materials, of a water-solublebenzyl tris (dialkylamino) phosphonium halide having the generalformula:

wherein R and R are selected from the group consisting of chlorine,bromine, and hydrogen atoms and alkyl radicals containing from 1 to 5carbon atoms, R" is an alkyl radical containing from 1 to 4 carbonatoms, and X is selected from the group consisting of chlorine andbromine, raising the temperature of the bath above 70 C., maintainingthe textile materials in contact with said bath at a temperature above70 C. until the materials are dyed and thereafter removing the textilematerials from the bath and rinsing and drying said materials.

4. A process according to claim 3, but further characterized in that thebenzyl tris (dialkylamlno) phosphonium halide is benzyltris(dimethylamino) phosphonium chloride.

5. A process according to claim 3, but further characterized in that thebenzyl tris(dialkylamino) phosphonium halide is benzyltris(dimethylamino) phosphoniurn bromide.

6. A process of dyeing textile materials composed of at least by Weightof a fiber-forming hydrophobic heteropolymer of at least 60% by Weightof acrylonitrile and not more than 40% by weight of a compoundcopolymerizable therewith having the grouping CH2=C which comprisesimmersing said textile materials in an aqueous bath containing a directcotton dyestutf and from 0.5 to by weight, based on the dry Weight ofsaid textile materials, of a water-soluble benzyl tris(dialkylamino)phosphonium halide having the general formula:

wherein R and R are selected from the group consisting of chlorine,bromine, and hydrogen atoms and alkyl radicals containing from 1 to 5carbon atoms, R is an acterized in that the benzyl tris(dia1kylamino)phosphonium halide is benzyl tris(dimethylamino) phosphoniumchloride.

8. A process according to claim 6, but further characterized in that thebenzyl tris(dialky1amino) phosphonium halide is benzyltris(dimethylamino) phosphonium bromide.

9. A process of dyeing textile materials of at least 10% by weight of ahydrophobic heteropolymer containing between about 85% and 99% by Weightof acrylonitrile and about 15 to 1% by weight of a compound having thegrouping CH2=C which comprises immersing said textile materials in anaqueous bath containing a direct cotton dyestuff and in the presence of0.1 to 15% by weight, based on the dry weight of said textile materials,of a water-soluble benzyl tris(diall ylamino) phosphonium halide havingthe general formula:

wherein R and R are selected from the group consisting of chlorine,bromine, and hydrogen atoms and alkyl radicals containing from 1 to 5carbon atoms, R" is an alkyl radical containing from 1 to 4 carbonatoms, and X is selected from the group consisting of chlorine andbromine, raising the temperature of the bath above C., maintaining thetextile materials in contact with said bath at a temperature above 70 C.until said textile materiais are dyed and thereafter removing thetextile materials from the bath and rinsing and drying said materials.

References Cited in the file of this patent UNITED STATES PATENTS2,015,864 Muller Oct. 1, 1935 2,254,965 ling Sept. 2, 1941 2,343,095Smith Feb. 29, 1944 2,543,316 Feiid Feb. 27, 1951 2,569,470 HagemeyerOct. 2, 1951 OTHER REFERENCES American Dyestuff Reporter for October 19,1936, pp. 561 to 565.

Journal Soc. Dyers and Col. for May 1945, pp. 122 to 125.

1. A DYEING PROCESS WHICH COMPRISES IMMERSING TEXTILE MATERIALS COMPOSEDOF AT LEAST 10% BY WEIGHT OF A FIBERFORMING HYDROPHOBIC HETEROPOLYMERCONTAINING AT LEAST 60% BY WEIGHT OF ACRYLONITRILE CONTAINING AT LEASTBY WEIGHT OF A COMPOUND COPOLYMERIZABLE THEREWITH HAVING THE GROUPINGCH2=<, AND CONTAINING A WATERSOLUBLE BENZYL TRIS (DIALKYLAMINO)PHOSPHONIUM HALIDE HAVING THE GENERAL FORMULA: